PluginHost

A simple subclass/subfolder plugin system.

Example: 

 class Generators
   extend PluginHost
   plugin_path 'app/generators'
 end

 class Generator
   extend Plugin
   PLUGIN_HOST = Generators
 end

 class FancyGenerator < Generator
   register_for :fancy
 end

 Generators[:fancy]  #-> FancyGenerator
 # or
 CodeRay.require_plugin 'Generators/fancy'
 # or
 Generators::Fancy
Methods
Constants
PluginNotFound = Class.new LoadError
  Raised if Encoders::[] fails because:
  • a file could not be found
  • the requested Plugin is not registered
HostNotFound = Class.new LoadError
PLUGIN_HOSTS = []
PLUGIN_HOSTS_BY_ID = {}
Public Class methods
extended(mod)

Adds the module/class to the PLUGIN_HOSTS list.

→ show source

# File lib/coderay/helpers/plugin.rb, line 72
      def extended mod
        PLUGIN_HOSTS << mod
      end
Public Instance methods
[](id, *args, &blk)

Returns the Plugin for id.

Example: 

 yaml_plugin = MyPluginHost[:yaml]
--- This method is also aliased as load ---

→ show source

# File lib/coderay/helpers/plugin.rb, line 49
    def [] id, *args, &blk
      plugin = validate_id(id)
      begin
        plugin = plugin_hash.[] plugin, *args, &blk
      end while plugin.is_a? Symbol
      plugin
    end
all_plugins()

Returns an array of all Plugins.

Note: This loads all plugins using load_all.

→ show source

# File lib/coderay/helpers/plugin.rb, line 151
    def all_plugins
      load_all
      plugin_hash.values.grep(Class)
    end
const_missing(const)

Tries to load the missing plugin by translating const to the underscore form (eg. LinesOfCode becomes lines_of_code).

→ show source

# File lib/coderay/helpers/plugin.rb, line 61
    def const_missing const
      id = const.to_s.
        gsub(/([A-Z]+)([A-Z][a-z])/,'\1_\2').
        gsub(/([a-z\d])([A-Z])/,'\1_\2').
        downcase
      load id
    end
default(id = nil)

Define the default plugin to use when no plugin is found for a given id, or return the default plugin.

See also map. 

 class MyColorHost < PluginHost
   map :navy => :dark_blue
   default :gray
 end

 MyColorHost.default  # loads and returns the Gray plugin

→ show source

# File lib/coderay/helpers/plugin.rb, line 114
    def default id = nil
      if id
        id = validate_id id
        raise "The default plugin can't be named \"default\"." if id == :default
        plugin_hash[:default] = id
      else
        load :default
      end
    end
list()

Returns an array of all .rb files in the plugin path.

The extension .rb is not included.

→ show source

# File lib/coderay/helpers/plugin.rb, line 140
    def list
      Dir[path_to('*')].select do |file|
        File.basename(file)[/^(?!_)\w+\.rb$/]
      end.map do |file|
        File.basename(file, '.rb').to_sym
      end
    end
load(id, *args, &blk)

Alias for #[]

load_all()

Loads all plugins using list and load.

→ show source

# File lib/coderay/helpers/plugin.rb, line 39
    def load_all
      for plugin in list
        load plugin
      end
    end
load_plugin_map()

Loads the map file (see map).

This is done automatically when plugin_path is called.

→ show source

# File lib/coderay/helpers/plugin.rb, line 159
    def load_plugin_map
      mapfile = path_to '_map'
      @plugin_map_loaded = true
      if File.exist? mapfile
        require mapfile
        true
      else
        false
      end
    end
map(hash)

Map a plugin_id to another.

Usage: Put this in a file plugin_path/_map.rb. 

 class MyColorHost < PluginHost
   map :navy => :dark_blue,
     :maroon => :brown,
     :luna => :moon
 end

→ show source

# File lib/coderay/helpers/plugin.rb, line 95
    def map hash
      for from, to in hash
        from = validate_id from
        to = validate_id to
        plugin_hash[from] = to unless plugin_hash.has_key? from
      end
    end
plugin_hash()

A Hash of plugion_id => Plugin pairs.

→ show source

# File lib/coderay/helpers/plugin.rb, line 133
    def plugin_hash
      @plugin_hash ||= make_plugin_hash
    end
plugin_path(*args)

The path where the plugins can be found.

→ show source

# File lib/coderay/helpers/plugin.rb, line 79
    def plugin_path *args
      unless args.empty?
        @plugin_path = File.expand_path File.join(*args)
      end
      @plugin_path ||= ''
    end
register(plugin, id)

Every plugin must register itself for id by calling register_for, which calls this method.

See Plugin#register_for.

→ show source

# File lib/coderay/helpers/plugin.rb, line 128
    def register plugin, id
      plugin_hash[validate_id(id)] = plugin
    end